Comment 2 for bug 385495

I've got signature splitting working on a branch with some caveats documented in http://bazaar.launchpad.net/~rossp/duplicity/signature-volsize/revision/575. Since the duplicity code and I aren't getting along, I won't be working on this further or using duplicity, but I wanted to leave my contributions here in case someone can pick them up and do something with them. But they should certainly be fully reviewed and the problems addressed before merging.